#include <bits/stdc++.h>
using namespace std;

class Task {
private:
    int n, m;
    int cc_nr;
    vector<vector<int>> adj;

public:
    Task() {
        this->cc_nr = 0;
    }

    void read() {
        ifstream fin("dfs.in");

        fin >> this->n >> this->m;

        adj.resize(this->n + 1);

        for (int x, y, i = 1; i <= this-> m; ++i) {
            fin >> x >> y;
            adj[x].push_back(y);
            adj[y].push_back(x);
        }

        fin.close();
    }

    void dfs(int node, vector<int> &vis) {
        vis[node] = 1;

        for (auto &neigh : this->adj[node])
            if (!vis[neigh])
                dfs(neigh, vis);
    }

    void solve() {
        vector<int> vis(this-> n + 1);

        for (int i = 1; i <= this->n; ++i) {
            if (!vis[i]) {
                dfs(i, vis);
                ++(this->cc_nr);
            }
        }
    }

    void print() {
        ofstream fout("dfs.out");

        fout << cc_nr;

        fout.close();
    }
};

int main()
{
    Task *task = new Task();

    task->read();
    task->solve();
    task->print();

    return 0;
}